1. Technical Field
The present invention relates to a droplet discharging head used as an inkjet head or the like, a manufacturing method thereof, and a droplet discharging device.
2. Related Art
As a droplet discharging head used to discharge droplets, an inkjet head mounted on an apparatus such as an inkjet recording apparatus is known. Generally, an inkjet head is equipped with a nozzle substrate containing a plurality of nozzle orifices that discharge ink droplets, a discharging chamber that is joined to this nozzle substrate and communicated with the nozzle orifices, and a cavity substrate containing an ink flow passage having, e.g., a reservoir. The inkjet head is structured in a manner that ink droplets are discharged from selected nozzle orifices by applying pressure to the discharging chamber using a driver and displacing a vibrating plate. The system of driving is, for example, an electrostatic drive system using electrostatic force, a piezoelectric drive system using a piezoelectric element, or a system using a heating element.
Miniaturization of such an inkjet head has been progressing. For example, JP-A-8-58089, which employs the piezoelectric drive system, discloses a laminate structure including an actuator, an ink-pressurizing chamber (discharging chamber), and a common ink chamber (reservoir) that are segmented on separate planes.
Another example is JP-A-2001-334663, which discloses an inkjet head including an actuator and an ink-pressurizing chamber provided in segments on different planes and a common ink chamber arranged perpendicular to these actuator and ink-pressurizing chamber.
Also, JP-A-2001-253072 and JP-A-2006-272574 disclose an edge-ejecting or face-ejecting system inkjet head that includes an actuator, an ink-pressurizing chamber, and a common ink chamber stacked on top of each other.
However, in accordance with these inkjet heads of the related art, what is now desired is a recording apparatus that can meet demands for higher recording density for finer printing and faster recording.
For this purpose, it is necessary to increase arrangement density of elements such as the ink flow passage and the actuator. Moreover, with further miniaturization of the head, it is required to further downsize the recording apparatus so as to enhance portability and freedom of installation.
To downsize the inkjet head along with the miniaturization of the ink flow passage and the actuator, it is required to shrink the area of portions for the common ink chamber, wiring, integrated circuit (IC) packaging, and the like that occupies a large area of the segments in the inkjet head.
To shrink the area for wiring and IC packaging, high-density packaging is generally performed. However, there are limitations in carrying out the wiring and IC packaging on the same plane as the plane for forming the actuator.
Also, when the common ink chamber is merely downsized, a problem occurs that the head loss increases in the common ink chamber during supply of ink because of the increase in the flow passage resistance in the common ink chamber, and that this may disturb stable and uniform discharge of ink droplets from the nozzles. Further, the miniaturization of the common ink chamber may cause a problem that the compliance of the common ink chamber decreases. This generates pressure interference among the nozzles via the common ink chamber, thereby disturbing stable and uniform discharge of ink droplets from the nozzles.